1. Field of the Invention
Various devices have been proposed for use as pedal devices in combination with a crank shaft for pedaling devices such as bicycles ever since the first cyclist experienced difficulty in maintaining proper contact with the pedal.
2. Prior Art
U.S. Pat. No. 554,686 teaches the use of vacuum cups upon which the foot of the cyclist will rest. U.S. Pat. No. 589,443 discloses a transverse groove in the bottom of the sole of a shoe for more efficient engagement of the pedal by the cyclist. U.S. Pat. No. 598,325 has a slot on the pedal which fits into a slot on the shoe for improved engagement of the pedal. U.S. Pat. No. 627,086 provides a heel and toe adjustment to the pedal so as to adjust the pedal to the length of the cyclist's foot. U.S. Pat. No. 637,900 discloses an attachment to an ordinary walking shoe which is then attached to the pedal as well. All of these devices provide for some engagement of the foot and the pedal so as to improve the efficiency during the downward stroke of the pedal.
U.S. Pat. No. 3,788,163 discloses a latching mechanism with a series of plates in a stack to be rotatably engaging a grid. U.S. Pat. No. 4,089,236 discloses a shoe with a lock means and jaws with a sole plate and an upper ramp surface. U.S. Pat. No. 3,964,343 teaches a pedal gripping means which is adapted to be secured to the sole using a prismatic configuration with two polyonal end surfaces and at least three mutually congruent side faces. Other more complicated devices could be contrived if excess weight and expense were not a major factor in bicycle pedal design.
While it is desirable to provide a pedal gripping means for the cyclist to efficiently engage the pedal, other considerations have become important in the ultimate enjoyment of a pedaling device. Clearly, any additional weight added to the cycle in the pedals increases the work required for propulsion without increasing the efficiency of the device. Devices which inhibit the rapid removal of the cyclist's foot from the pedal are clearly unsafe. Devices which inhibit the rider's quick and troublefree insertion of his foot on the pedal oftentimes defeat the efficiencies of the device and are also unsafe. Rapid insertion and removal of the foot is needed so that the bike does not tip over when coming to a stop. Also being able to start quickly in traffic is important, and delay in engaging the pedal should be eliminated.